Question

the measure of an angle is 150°. what is the measure of its supplementary angle?

Explanation:

Step1: Recall supplement - angle formula

The sum of an angle and its supplementary angle is 180°. Let the given angle be $\alpha = 150^{\circ}$ and its supplementary angle be $\beta$. Then $\alpha+\beta = 180^{\circ}$.

Step2: Solve for the supplementary angle

We can rewrite the formula as $\beta=180^{\circ}-\alpha$. Substitute $\alpha = 150^{\circ}$ into the formula: $\beta = 180^{\circ}-150^{\circ}=30^{\circ}$.

Answer:

$30^{\circ}$